Blue John Oval Links 9ct Yellow Gold Bracelet. B190. This exquisite link bracelet features eight unmissable oval shaped Blue John stones that have been sourced directly from Treak Cliff Cavern in Castleton. The Blue John stone has then been set onto a delicate 9ct yellow gold link chain and is completed by a classic lobster clasp for easy wear. All our Blue John jewellery is designed and crafted within our very own workshops in Ashbourne, Derbyshire where a team of skilled craftsmen turn the raw Blue John stone in these stunning pieces of jewellery. You can find other matching Blue John jewellery and other Blue John bracelets on our website. 9ct Yellow Gold and Blue John.